I looked but didn't find this already mentioned. Again, not sure if it's a limitation of SoundCloud, but it would be nice somewhere down the line to be able to queue up tracks.
Say you want to start with track 1, but right after you want it to go to track 2. A queue system would allow that to be smoother than pausing what you're doing as the GM at the right time and pressing the next track.
Would let you make your own 'campaign soundtrack' or even page soundtrack that would take minimal micro-management.
Something down the road, perhaps?